BABBQ5 - Automated Testing for Modern Android Applications

How to use dependency injection, mocking, and a test runner to automate UI & unit testing. Sample app source on GitHub: https://github.com/abdyer/android-test-demo

Transcript

1. AUTOMATED TESTING FOR
   Modern ANDROID
   APPLICATIONS
   

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2. ANDY DYER
   +AndrewDyer || @dammitandy
   

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4. MUSIC LIBRARY
   

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5. WRIST PRESENTER
   

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6. RECORDS,
   COFFEE & BEER
   

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7. "Ich lerne Deutsch."
   

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8. MAKING ANDROID APPS TESTABLE
   

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9. DYNAMIC LANGUAGES
   "Tests shouldn't drive implementation."
   

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10. STATIC LANGUAGES
    "You know nothing."
    

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11. MAKING ANDROID APPS TESTABLE
    ▸ Dependency injection
    ▸ Mocking & stubbing
    ▸ Unit & integration tests
    

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12. DEPENDENCY INJECTION
    

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13. DEPENDENCY INJECTION
    ▸ Decouples application components
    ▸ Classes receive dependencies, don’t have to know where to find
    them or how to create them
    ▸ Makes it easy to swap components for mocks in tests
    

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14. BASIC DEPENDENCY INJECTION
    public class Beer {
    Water water;
    Barley barley;
    Hops hops;
    public Beer(Water water, Barley barley, Hops hops) {
    this.water = water;
    this.barley = barley;
    this.hops = hops;
    }
    }
    

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15. DAGGER
    A Java dependency injection library
    

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16. DAGGER
    ▸ Define dependencies at compile time to avoid reflection at runtime
    ▸ Compiler validates modules and injections
    ▸ Jake Wharton “Architecting Android Applications with Dagger"
    goo.gl/JIM7KI
    square.github.io/dagger
    

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17. DAGGER MODULES
    @Module(injects = {MyActivity.class, MyFragment.class})
    public class MyModule {
    @Provides @Singleton
    public MyService provideMyService() {
    return new MyService();
    }
    }
    

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18. DAGGER OBJECT GRAPH
    public class MyApplication extends Application {
    private dagger.ObjectGraph objectGraph;
    @Getter static MyApplication instance;
    @Override
    public void onCreate() {
    super.onCreate();
    instance = this;
    objectGraph = dagger.ObjectGraph.create(new MyModule());
    }
    public void inject(Object dependent) {
    objectGraph.inject(dependent);
    }
    }
    

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19. DAGGER DEPENDENCY INJECTION
    public class MyFragment extends Fragment {
    @Inject MyService service;
    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
    MyApplication.getInstance().inject(this);
    service.getMyData();
    }
    }
    

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20. MOCKING & STUBBING
    

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21. MOCKING & STUBBING
    ▸ Substitute runtime implementation for something that can be
    predictably tested in isolation
    ▸ Verify behavior
    

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22. MOCKITO
    A Java mocking library
    

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23. MOCKITO
    ▸ Mock/stub dependencies and function return values
    ▸ Inject mocks to validate behavior in tests
    ▸ Use included Hamcrest matchers for clear, readable tests
    code.google.com/p/mockito/
    

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24. USING MOCKITO
    MyClass mocked = mock(MyClass.class);
    // code to inject mock & load activity/fragment
    // ...
    verify(mocked).getMyData(anyInt(), anyString());
    

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25. UNIT & INTEGRATION TESTS
    

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26. "Tests or it didn't happen."
    

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27. ESPRESSO
    An Android UI test library
    

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28. ESPRESSO
    ▸ Handles activity creation & state sync
    ▸ Simple, concise API
    ▸ Really fast!
    code.google.com/p/android-test-kit
    

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29. USING ESPRESSO
    public class MyActivityTest extends ActivityInstrumentationTestCase2 {
    public MyActivityTest() { super(MyActivity.class); }
    @Override
    protected void setUp() throws Exception {
    super.setUp();
    getActivity(); // trigger activity launch
    }
    public void testInvalidEmailShowsError() {
    onView(withId(R.id.email)).perform(typeText("abc"), closeSoftKeyboard());
    onView(withId(R.id.email_sign_in_button)).perform(click());
    onView(withId(R.id.email)).check(matches(withError(
    getActivity().getString(R.string.error_invalid_email))));
    }
    }
    

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30. SAMPLE APPLICATION OVERVIEW
    ▸ Retrofit API with sample requests
    ▸ Dagger module
    ▸ Lombok & Android Studio plugin
    ▸ Login activity
    ▸ Activity with list fragment to make API request and display data
    

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31. HABEN SIE FRAGEN?
    

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32. CODE & SLIDES
    github.com/abdyer/android-test-demo
    

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